Need to read again and in more detail but my understanding is sundance and the other treeper are incorrect in their opinions. The burden is on the FBI to prove a compelling need to continue witholding information
DOJ Seal
Freedom of Information Act Guide, May 2004
Exemption 7(A)
The first subpart of Exemption 7, Exemption 7(A), authorizes the withholding of "records or information compiled for law enforcement purposes, but only to the extent that production of such law enforcement records or information . . . could reasonably be expected to interfere with enforcement proceedings." (1) The Freedom of Information Reform Act of 1986, often referred to as the 1986 FOIA amendments, lessened the showing of harm required from a demonstration that release "would interfere with" to "could reasonably be expected to interfere with" enforcement proceedings. (2) The courts have recognized repeatedly that the change in the language for this exemption effectively broadens its protection. (3)
Determining the applicability of this Exemption 7 subsection thus requires a two-step analysis focusing on (1) whether a law enforcement proceeding is pending or prospective, and (2) whether release of information about it could reasonably be expected to cause some articulable harm. (4) The courts have held that the mere pendency of enforcement proceedings is an inadequate basis for the invocation of Exemption 7(A); the government must also establish that some distinct harm could reasonably be expected to result if the record or information requested were disclosed. (5) For example, the Court of Appeals for the District of Columbia Circuit has held that the fact that a judge in a criminal trial specifically delayed disclosure of certain documents until the end of the trial is alone insufficient to establish interference with that ongoing proceeding. (6)
It is beyond question that Exemption 7(A) is temporal in nature and is not intended to "endlessly protect material simply because it [is] in an investigatory file." (7) Thus, as a general rule, Exemption 7(A) may be invoked so long as the law enforcement proceeding involved remains pending, (8) or so long as an enforcement proceeding is fairly regarded as prospective (9) or as preventative. (10)
Although Exemption 7(A) is temporal in nature, it nevertheless remains viable throughout the duration of long-term investigations. (11) For example, in 1993 it was held applicable to the FBI's continuing investigation into the 1975 disappearance of Jimmy Hoffa. (12) Even when an investigation is dormant, Exemption 7(A) has been held to be applicable because of the possibility that the investigation could lead to a "prospective law enforcement proceeding." (13) The "prospective" proceeding, however, must be a concrete possibility, rather than a mere hypothetical one. (14)
Further, even after an enforcement proceeding is closed, courts have ruled that the continued use of Exemption 7(A) may be proper in certain in-stances. One such instance involves "related" proceedings, i.e., those instances in which information from a closed law enforcement proceeding will be used again in other pending or prospective law enforcement proceedings -- for example, when charges are pending against additional defendants (15) or when additional charges are pending against the original defendant. (16)
Another circumstance in which the continued use of Exemption 7(A) has been held proper involves post-conviction motions, i.e., those instances in which the requester has filed a motion for a new trial or has otherwise appealed the court's action. (17) The extent of protection in such a circumstance, however, varies; some courts have limited Exemption 7(A) protection to only the material not used at the first trial, (18) while other courts in some cases have extended Exemption 7(A) protection to all of the information compiled during all of the law enforcement proceedings. (19)
Similarly, Exemption 7(A) also may be invoked when an investigation has been terminated but an agency retains oversight or some other continuing enforcement-related responsibility. (20) For example, it has been found to have been invoked properly to protect impounded ballots where their disclosure could "interfere with the authority of the NLRB" to conduct and process future collective bargaining representation elections. (21) If, however, there is no such ongoing agency oversight or continuing enforcement-related responsibility, courts do not permit an agency to continue the use of Exemption 7(A) to protect information. (22)
The types of "law enforcement proceedings" to which Exemption 7(A) may be applicable have been interpreted broadly by the courts. (23) Such proceedings have been held to include not only criminal actions, (24) but civil actions (25) and regulatory proceedings (26) as well. They include "cases in which the agency has the initiative in bringing an enforcement action and those . . . in which it must be prepared to respond to a third party's challenge." (27) Enforcement proceedings in state courts (28) and foreign courts (29) also qualify for Exemption 7(A) protection.
http://www.justice.gov/oip/exemption7a.htm